This invention concerns shackles of the type that transport poultry carcasses in sequence along a processing path, particularly through the cut-up line where the poultry carcasses are cut apart. More particularly, the invention concerns the method and apparatus for realigning the stirrups of the poultry shackle as the birds begin movement along a processing path.
In the automated processing of poultry, it is common practice to suspend previously eviscerated, oven-ready poultry carcasses by their legs from shackles that are moved along a suspended conveyor system through a processing plant. The shackles have stirrups that support the legs of the birds, and the shackles can be turned about their upright axes as they advance along the processing path so as to present the birds at different orientations for weighing the bird or for the cutting process. For example, the birds may be turned sideways for advancement through a cutting station where the breast of the bird is to be cut, or turned so that the breast of the bird faces forwardly as the wings or other appendages are cut.
In order to properly cut the birds, the birds must be properly oriented at the beginning of the cutting line. In some instances, the shackles will not be properly oriented because the last step in the prior run has the shackles improperly oriented, or it is convenient to have the shackles turned sideways for hanging the birds on the shackles but the first cutting step might require the birds to be facing forwardly or rearwardly instead of to the side. Also, it is not unusual to have a few of the oncoming poultry shackles improperly oriented because of some activity up the line of the conveyor system.
If the birds are improperly oriented as they start through the cut-up line, the cutting processes will not be properly performed, and it is highly likely that the birds will be damaged because of the wrong orientation of the birds moving into a cut-up station.
This invention is directed to an improved, durable and accurate self realigning rotary shackle that reliably orients the shackle and the bird carried by the shackle to the proper orientation to start through the next processing station of a poultry processing line.
Briefly described, the present invention comprises a self realigning rotary shackle for transporting poultry carcasses along a poultry processing line that reorients the shackles that are not already properly aligned in the processing line so that the shackle, together with any bird carried by the shackle, is properly oriented for the next processing station. The shackle assembly includes a turning block that engages turning pins at the entry of the various processing stations. The turning block is approximately square and includes turning slots at its corners that engage and xe2x80x9cwalk aroundxe2x80x9d turning pins that are positioned along the path of the turning block. Upon engaging a turning pin, the turning block will rotate 90xc2x0. The turning block can be rotated 180xc2x0 upon engagement of two consecutive turning pins. The turning block can be rotated in either direction by engaging turning pins on opposite sides of its processing path.
The turning block includes opposed side edges or xe2x80x9cwingsxe2x80x9d that are positioned radially from the axis of rotation of the turning block. One of the side wings includes a relief in its lower edge portion that intersects the adjacent turning slots. The relief extends high enough into the turning block so that the edge portion of the turning block above the relief fails to engage the turning pins. With this arrangement, the turning block and therefore the stirrup of the shackle assembly will be engaged by the turning slots so as to rotate the stirrup to the proper orientation, but when the stirrup is properly oriented, the relief of the turning block will be in its position to pass over the next turning pin(s), thereby leaving the turning block and the stirrups unturned. Usually, there will be three turning pins in a row so that no matter what orientation the stirrups are in as the shackle approaches the turning pins, the shackle will be rotated up to three times until the relief passes over any subsequent turning pins so as to achieve proper orientation of the stirrups.
In the disclosed embodiment, the turning block is telescopically and releasably mounted to a conveyor connector that always extends in alignment with the conveyor line. When the turning block is to be rotated by engagement with turning pins, the turning block is lifted against the bias of a spring away from the conveyor connector so as to become unlocked from the conveyor connector. The turning block is then free to rotate in response to engagement by the turning pins so as to effect the rotary movement of the stirrup of the shackle assembly. When the turning has been achieved, the turning block is released and the spring urges the turning block and conveyor connector back into engagement with each other so that they become locked together once again.
Another feature of the invention is at least one beam interrupter is fixedly mounted to and movable in unison with the shackle, so that the orientation of the shackle stirrups can be ascertained as the shackle assembly moves by a detector. This feature of the invention is used to shut down the conveyor line in the event that one or more of the shackles has become disoriented, so as to avoid movement of birds through the processing stations in wrong orientation.
Thus, it is an object of this invention to provide and improve shackle assembly for transporting poultry carcasses along a poultry processing line, so that the stirrups of the shackles will be properly oriented as the birds carried by the shackles are advanced to a cutting station.
Another object of this invention is to provide an improved shackle assembly for transporting poultry carcasses, wherein a turning block is configured to engage and turn about turning pins until a modified wing portion of the turning block is moved about the turning pins without turning the shackle, thereby assuring that the stirrups of the shackle are properly oriented for advancement of its bird into a cutting station.
Another object of this invention is to provide an improved method of orienting birds carried on a poultry processing line for proper cutting or other processing steps at the processing stations at positions along the processing line.
Other objects, features and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.